Time-dependent alginate/polyvinyl alcohol hydrogels as injectable cell carriers

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Polymer Chemistry

Background:

• Alginate hydrogels are widely used as cell carriers but suffer from rapid gelation and lack of injectability.
• Existing injectable alginate systems using calcium sulfate or carbonate have limitations in gelation control.
• There is a need for injectable hydrogels with tunable properties for effective cell delivery.

Purpose of the Study:

• To develop injectable alginate/polyvinyl alcohol (PVA) blend hydrogels with a controllable gelation rate.
• To investigate the effect of cross-linking agent and retardation agent ratios on gelation kinetics.
• To evaluate the in vitro cell compatibility and chondrogenic potential of the developed hydrogels.

Main Methods:

• Alginate/PVA blend hydrogels were prepared using calcium sulfate (CaSO4) as a cross-linking agent and sodium phosphate (Na2HPO4) as a retardation agent.
• The ratio of CaSO4/Na2HPO4 was adjusted to control the gelation rate.
• In vitro cell culture of human chondrocytes was performed to assess cell viability, proliferation, and glycosaminoglycan (GAG) production over 28 days.

Main Results:

• Controllable gelation rates were achieved by adjusting the CaSO4/Na2HPO4 ratio, with increased Na2HPO4 and decreased CaSO4 leading to slower gelation.
• Alginate and PVA exhibited good compatibility, with minimal PVA extraction observed over 7 days.
• Chondrocytes showed linear growth and increased GAG content in alginate/PVA hydrogels, particularly those with higher PVA content, indicating enhanced cell viability and activity.

Conclusions:

• Injectable alginate/PVA blend hydrogels with tunable gelation kinetics were successfully fabricated.
• The developed hydrogels demonstrate excellent biocompatibility and support chondrocyte proliferation and function.
• These findings suggest that alginate/PVA hydrogels are promising candidates for injectable cell carrier applications in tissue engineering.